<template>
  <el-container class="home-container">
    <!-- 头部区域 -->
    <el-header>
      <div>
        <img src="../assets/logo.png" alt />
        <span>电商管理后台系统</span>
      </div>
      <el-button type="info" @click="logout">退出</el-button>
    </el-header>
    <!-- 页面主题区域 -->
    <el-container>
      <!-- 侧边栏 -->
      <el-aside :width="isCollapse ? '64px' : '200px'">
        <div class="toggle-button" @click="toggleCollapse">|||</div>
        <!-- 菜单分为两级,并且可以折叠,这是菜单区域 -->
        <el-menu
          background-color="#333744"
          text-color="#fff"
          active-text-color="#409eff"
          :unique-opened="true"
          :collapse="isCollapse"
          :collapse-transition="false"
          :router="true"
          :default-active="path"
        >
          <!-- 一级菜单 -->
          <el-submenu :index="item.id+''" v-for="(item) in menulist" :key="(item.id)">
            <!-- 一级菜单模板区域 -->
            <template slot="title">
              <!-- 图标 -->
              <i :class="iconsObj[item.id]"></i>
              <!-- 文本 -->
              <span slot="title">{{item.authName}}</span>
            </template>
            <!-- 二级菜单 -->
            <el-menu-item
              :index="'/'+subitem.path"
              v-for="(subitem) in item.children"
              :key="(subitem.id)"
              @click="saveNavState('/'+subitem.path)"
            >
              <!-- 二级菜单模板区域 -->
              <!-- 图标 -->
              <i class="el-icon-menu"></i>
              <!-- 文本 -->
              <span slot="title">{{subitem.authName}}</span>
            </el-menu-item>
          </el-submenu>
        </el-menu>
      </el-aside>
      <!-- 右侧主要内容 -->
      <el-main>
        <!-- home页面的路由占位符,就是右侧内容区域显示的路由 -->
        <router-view></router-view>
      </el-main>
    </el-container>
  </el-container>
</template>

<script>
export default {
  data () {
    return {
      // 左侧菜单列表数据
      menulist: [],
      // 字体图标对象
      iconsObj: {
        125: 'iconfont icon-users',
        103: 'iconfont icon-tijikongjian',
        101: 'iconfont icon-shangpin',
        102: 'iconfont icon-danju',
        145: 'iconfont icon-baobiao'
      },
      // 是否折叠
      isCollapse: false,
      // 被激活的链接地址
      path: ''
    }
  },
  // 在页面刚加载的时候就立即获取左侧菜单 这里用到生命周期created
  created () {
    this.getMenuList()
    // this.path = window.sessionStorage.getItem('activePath')
  },
  methods: {
    logout () {
      window.sessionStorage.clear()
      this.$router.push('/login')
    },
    // 获取所有的菜单
    async getMenuList () {
      // 通过解构赋值拿到需要的列表数据
      const { data: res } = await this.$http.get('/menus')
      // 如果获取列表成功,就渲染列表,否则给出错误提示
      if (res.meta.status !== 200) return this.$message.error(res.meta.msg)
      // console.log(res.data)
      this.menulist = res.data
    },
    // 点击按钮切换菜单的折叠与展开
    toggleCollapse () {
      this.isCollapse = !this.isCollapse
    },
    // 点击保存二级菜单时保存当前的path值 保存连接激活状态
    saveNavState (activePath) {
      window.sessionStorage.setItem('activePath', activePath)
      this.path = window.sessionStorage.getItem('activePath')
    }
  }
}
</script>

<style lang="less" scoped>
.home-container {
  height: 100%;
}
.el-header {
  background-color: #373d41;
  display: flex;
  justify-content: space-between;
  align-items: center;
  color: #fff;
  font-size: 20px;
  > div {
    display: flex;
    align-items: center;
  }
  img {
    width: 60px;
    height: 60px;
  }
  span {
    margin-left: 15px;
  }
}
.el-aside {
  background-color: #333744;
  .el-menu {
    border-right: 0;
  }
  .toggle-button {
    text-align: center;
    font-size: 10px;
    line-height: 24px;
    color: #fff;
    background-color: #475163;
    letter-spacing: 0.2em;
    cursor: pointer;
  }
}
.el-main {
  background-color: #eaedf1;
}
.iconfont {
  margin-right: 10px;
}
</style>
